The recent high cost of fossil fuels such as oil, natural gas and coal plus the increase demand for energy have lead to an increased awareness of an acute need for alternative sources of energy. This awareness has been exacerbated by the concern for a supply of energy at reasonable cost, a critical need for energy independence and the economic impact on the United States of America's economy. Accordingly, there is and has been an increased emphasis on search for a better way to provide energy and at the same time to do so in an environmentally friendly manner.
It is and has been well known for many years that exposure of a material to solar rays causes an increase in the material's temperature. It is also well known that focusing the sun's rays can be used to heat an energy absorbing liquid such as water to generate steam for heating a facility or structure or for generating electrical energy. Therefore, in this time of diminishing natural resources, increased energy cost and environmental concerns, the use of solar energy, a virtually inexhaustible resource, offers an economical, efficient limitless and environmentally safe alternative for fossil fuels.
Since the early 1980's and until the present there have been a number of approaches for harnessing solar energy. For example, a U.S. patent of Cohen, U.S. Pat. No. 4,469,938 discloses a solar tracking system. As disclosed, the system provides a relatively lightweight solar collector that is properly positioned with respect to the sun. A parabolic reflector surface is included to provide a line of focus of the sunlight directed toward a cylindrical energy absorption tube. Photovoltaic cells provided on either side of the energy absorption tube are directed toward the parabolic reflector surface. A reversible motor is electrically connected to the cells and physically connected to the reflector system for correcting any misalignment with respect to the sun. The reversible motor can be used as the sole means for powering the tracking system or can be used in conjunction with an outside power source.
A more recent approach for the use of solar energy is disclosed in a U.S. Pat. No. 5,191,876 of Atchley. The Atchley patent discloses a lightweight rotatable solar collection system supported overhead with a parabolic reflector trough which continuously rotates about a fluid filled collection conduit located at the trough's focal point. The system is supported overhead preventing bending of the collection conduit, ensuring that solar rays reflected off the trough will continuously focus on the conduit. A tracking system, cooperating with the reflection assembly, monitors the location of the sun cuing the motor when rotation of the torugh is required for maximum heat collection. The efficiency acquired through a reflection assembly supported and braced overhead and used in cooperation with a system monitoring movement of the sun, allows solar heat collection for operation of a cooling and heating unit economically.
Additionally, a U.S. Pat. No. 7,331,178 of Goldman discloses a hybrid generator with alternative fuel sources for generating electricity from both solar and non-solar sources. The solar generating portion of the facility includes capability to directly generate electricity from solar insulation or to store the solar energy in a tangible medium including stored heat, or solar generating fuel. The generating facility is configured to generate electricity simultaneously from both solar and non-solar sources, as well as solely from immediate solar isolation and from solar energy stored in a tangible medium. Additionally, the solar generating capacity may be segregated; such that separate spectra of solar isolation are used to capture heat for a steam turbine based electrical generator, capture light energy for photovoltaic based electrical generation, and to grow biomass to generate a solar fuel.
Notwithstanding the above, it is presently believed that there is a need and a potential market for an improved solar tracking unit for a steam generator or the like. There should be a need for such devices because they position a mirror about two axis that are perpendicular to one another and incorporate a self-locking feature to provide stability. It is also believed that the devices in accordance with the present invention will tend to optimize the heating of a heat absorbable fluid, maximize the output of work in a more efficient manner than conventional units. Further, it is believed that the devices in accordance with the present invention can be manufactured efficiently and sold at a competitive price, will be durable in use, relatively easy to install and service and at the same time produce energy in an environmentally friendly manner, reduce the dependence on fossil fuels and used for a number of different applications.